<template>
  <div>
    <h1>当前求和为：{{ sum }}</h1>
    <h1>当前求和为：{{ bigSum }}</h1>
    <h1>我在{{ school }}，学习{{ subject }}</h1>

    <!-- v-model绑定默认的选择数字 -->
    <select v-model.number="n">
      <option value="1">1</option>
      <option value="2">2</option>
      <option value="3">3</option>
    </select>
    <button @click="increment">+</button>
    <button @click="decrement">-</button>
    <button @click="incrementOdd">当前为奇数加</button>
    <button @click="incrementWait">等一等再加</button>
  </div>
</template>

<script>
import { mapState, mapGetters } from "vuex";
export default {
  name: "Count",
  data() {
    return {
      n: 1,
    };
  },
  methods: {
    increment() {
      this.$store.commit("JIA", this.n);
    },
    decrement() {
      this.$store.commit("JIAN", this.n);
    },
    incrementOdd() {
      this.$store.dispatch("jianOdd", this.n);
    },
    incrementWait() {
      this.$store.dispatch("jianWait", this.n);
    },
  },
  computed: {
    // 靠程序员自己亲自去写计算属性
    // sum() {
    //   return this.$store.state.sum;
    // },
    // subject() {
    //   return this.$store.state.subject;
    // },
    // school() {
    //   return this.$store.state.school;
    // },

    // ...mapState es6写法，会直接将mapState一一展开在computed对象中
    // 借助mapState生成计算属性，从state中读取数据（对象写法）
    // ...mapState({ sum: "sum", school: "school", subject: "subject" }),
    // 借助mapState生成计算属性，从state中读取数据（数组写法）
    ...mapState(["sum", "school", "subject"]),

    // bigSum() {
    //   return this.$store.getters.bigSum;
    // },

    // 借助mapGetterse生成计算属性，从getters中读取数据（对象写法）
    ...mapGetters({ bigSum: "bigSum" }),
    // 借助mapState生成计算属性，从state中读取数据（数组写法）
    ...mapGetters(["bigSum"]),
  },
};
</script>

<style scoped>
button {
  margin-left: 5px;
}
</style>